Pin joints are employed on many types of residential and industrial machinery and equipment, for instance to provide pivot points between adjoining components. Most pin joints include various assemblies and structures intended to help prevent premature breakage or wear, for instance components that define chambers for holding lubricant. However, radial and axial loads endured by pin joints can be extreme, causing high mechanical and thermal stress and strain of pin joint assemblies. Such stress and strain can not only cause component breakage and wear, it can cause leakage or release of lubricant, which in turn can lead to further component breakage and wear as well as environmental pollution. In fact, some machinery and equipment are even designed to regularly pump fresh lubricant into pin joints in order to replace continually leaking lubricant. As demands on pin joint assemblies increase in succeeding generations of machinery and equipment, more robust pin joint assembly designs are needed.
U.S. Pat. No. 7,309,186 to Oertley (“Oertley '186”), which, like the present application and invention, is assigned to Caterpillar Inc., discloses a pin cartridge for a pin joint. Specifically, Oertley '186 describes a pin cartridge assembly that includes a pin, a bushing, a collar at each end of the pin, and a sleeve bearing between each end of the bushing and the pin. Two-element seals known to those of ordinary skill in the art as “can and lip” seals help retain lubricant in the pin cartridge.